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<title>Atlas software user guide -- Download</title>
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<h2>Download and installation</h2>
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<p>
<i>Last updated: October 15, 2005</i>&nbsp;
<a href="http://atlas.math.umd.edu/software/atlas.tgz">
download the program now</a> 
</p>

<p>
These installation instructions are directed primarily towards users operating
in a unix/linux environment. Macintosh (system X) users should also be able to
install the program. Windows users are on their own; at the very least, they
need to install a C++ compiler (say GNU gcc), and GNU make (if that is possible
at all) or an equivalent.
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<p>
The software is provided in the form of a compressed tarfile. 
Saying "tar xzf name_of_tarfile" will create a directory called 
"atlas_version-number". You should then descend into that directory and say
"make"; this should create an executable named "atlas", in that same directory.
Depending on your path configuration, you launch the program by typing "atlas" 
or "./atlas".
</p>

<h4>Note on compilers</h4>

<p>
The makefile calls the g++ compiler by default; if this is not available on
your system, you should edit the makefile and replace it by the C++ compiler
that you have. I will be interested to hear how the
program fares with other compilers---but unfortunately I cannot promise any
help with compilation problems (unless they originate from obvious bugs in
the program.) The program has successfully compiled and run in the following
environments:
</p>

<dl>
<dt>g++ (at least 3.0, and up to 3.4.4):</dt>
<dd><ul>
<li>Intel Pentium and Xeon under Linux</li>
<li>Macintosh (system X)</li>
<li>AMD Opteron under Linux</li>
</ul></dd>
<br>
<dt>icc (Intel C++ compiler)</dt>
<dd><ul>
<li>Intel Pentium and Xeon under Linux</li>
</ul></dd>
</dl>

<p>
The Intel compiler is very fussy, and with the very verbose compilation flags
that are set by default (-Wall), it will drown you in "remarks". More 
seriously, it does not compile the headers for the GNU readline library, at
least on my system. Therefore it is recommended to suppress the -Wall flags,
and to compile with "make readline=false" (see below).
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<p>
The program is known to <i>not</i> compile in the following environments:
<dl>
<dd><ul>
<li>g++ 2.96 or lower (to discover the version of g++ installed on your system,
type "gcc -v" at the shell command line);</li>
</ul></dd>
<a name="readline"></a>
</dl>
</p>

<h4>Note on readline</h4>

By default, the program uses the GNU 
<a href="http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html">readline</a> 
library for its command line interaction. If this is not available on your 
system, or if you have compilation trouble because of it, you may turn it off 
by saying "make readline=false". This will still give you a fully functional
program, but without the creature comforts such as command history, command
line editing and tabbed command completion that readline provides for you.
See <a href="interface.html">here</a> for more details.

<h4>Note on configuration</h4>

The program is not currently provided with any sophisticated configuration
and installation scripts, although it is intended to do this at some point in 
the future. The current preliminary versions are intended for personal use. In 
particular, it is important that the program is executed in the same "atlas..."
directory in which it was compiled, or else it will fail to find the files it 
needs for help messages. If it is desired to install the program for multi-user
usage, this problem is easily remedied by changing the MESSAGE_DIR constant
in sources/interface/io.h to the absolute pathname of the "messages" directory.

<hr>

<p>
<a href="userintro.html">Back</a> to the introduction.<br>
<a href="http://atlas.math.umd.edu">Back</a> to the Atlas homepage.
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